Prevalence of cardiac valve abnormalities in afebrile injection drug users

Objectives: To determine the prevalence of occult valvular pathology in afe brile injection drug users (IDUs) compared with an afebrile, non-IDU popula tion. To characterize the type of valvular pathology present in light of cu rrent recommendations regarding periprocedural antibiotic prophylaxis again st endocarditis. Methods: This was a comparative, cross-sectional study inv olving a convenience sample of 98 patients with a history of injection drug use, and 99 non-IDU patients presenting to a large urban ED. Patients were excluded if they had one or more of the following: a history of cardiac va lve abnormality, a history of endocarditis, fever on presentation, or a car diac murmur. Data were collected that included demographics, medical histor y, and details of injection drug use. Transthoracic echocardiography (echo) was performed on each subject in the ED, and read in a blinded fashion by a single board-certified cardiologist. Results: Among 98 IDUs and 99 non-ID Us, 12% of the IDUs had aortic valve thickening, compared with 5.1% of the non-IDUs (99% CI for difference of 7.8% = -3.0% to 18.6%). Forty-four perce nt of the IDUs had mitral valve thickening, compared with 25% of the non-ID Us (99% CI for difference of 18.3% = 0.9% to 35.7%). Eleven percent of the IDUs vs 1% of the non-IDUs had tricuspid valve thickening (99% CI for diffe rence of 10.4% = 1.6% to 19.2%). No patient had pulmonic valve thickening. Six percent of the IDUs vs 0% of the non-IDUs had mitral annulus thickening (99% CI for difference of 6.3% = -0.1% to 12.8%). Twelve percent of the ID Us vs 3% of the non-IDUs had mitral chordae thickening (99% CI for differen ce of 9.5% = -0.4% to 19.4%). Tricuspid chordae thickening was recorded in 2% of the IDUs vs O% of the non-IDUs (99% CI for difference of 2.1% = -1.7% to 6.0%). Most important, the prevalence of valvular regurgitation was sma ll, and evenly distributed in the two groups. No valvular vegetations were seen. Conclusion: Both non-IDUs and IDUs have occult valvular pathology, Th ere is an increased prevalence in IDUs of tricuspid and mitral valve thicke ning. The prevalence of valvular regurgitation, a reported indication for p eriprocedural antibiotic prophylaxis, was small and the affected valves wer e not statistically different between the two groups. These findings questi on the selected routine use of antibiotic prophylaxis in IDU patients under going invasive procedures.